1. Field of the Invention
The present invention is drawn to novel and inventive apparatus and processes employing, choke means at least partially providing restriction to passage of material, and measurement of magnitude of force(s) exerted on said choke means by passage of material, in order to provide: a characterization of the material; and/or control of the passage of material and/or control of processes or apparatus associated with the passage of material, in response to the magnitude of the measured force(s).
2. Description of the Prior Art
In regard to characterization of extrudeable material, one prior art device for evaluating texture or degree of cooking is a "Texturepress" sold by the Food Texture Corporation (Rockville, Md.). With this prior art device, texture is evaluated by measuring the force required to back extrude material in a back extrusion cup with a fixed annular gap. The prior art device suffers from the disadvantages of: (1) requiring that a sample must be manually removed from the processing line (i.e. the prior art device is not automatic or in-line); (2) possible requiring sample preparation (e.g. processing or conditioning) prior to evaluation; (3) the prior art device utilizes batch rather than continuous operation; (4) the force measurement must be interpreted; (5) such manual sample manipulation and interpretation, increase the probability of errors; (6) only subsequent to said interpretation may adjustments in the processing line parameters be made, thus necessitating a time delay between when the sample is taken and when the adjustments may be made.
In regard to evaluation of degree of cooking, the only prior art test for degree of cooking of potatoes in preparation for production of potato flakes known to the present inventors involves placing cooked mashed potatoes on a sieve and running hot water over the potatoes and through the sieve. Allegedly the number and size of the potatoe pieces remaining on the sieve reflects the degree to which the potatoes are cooked. For French fried potatoes, a prior art test for degree of cooking involves taking a sample of cooked french fries, and measuring the degree to which they deflect under a known force. Presumably the degree of deflection is an indication of the degree to which they are cooked. Clearly such tests are not in-line, not continuous, not automatic, require manual labor, do not operate in real-time with the cooking, may require sample preparation, and are apparently inaccurate.
Another prior art device is disclosed in U.S. Pat. No. 3,470,584 issued 10/7/69 to Iwata et al which includes: a restriction formed between a valve and an outlet of a feed apparatus, and distance indicating means for indicating the clearance distance between said valve and said outlet of said feed apparatus. However, said distance indicating means is not taught by Iwata et al to be useful for (nor will said means function for) measuring the magnitude of force applied to the valve by passage of material through the restriction. The distance indicating means of Iwata et al is precluded from functioning to indicate the magnitude of force applied to the valve by passage of material through said restriction, at least by the presence of varying forces on the valve other than the force applied by passage of material through said restriction e.g. varying reduced pressure in the reduced pressure chamber, lodging of lumps in the clearance between the outlet and the valve, varying pressures applied to each side of the piston 26. The device of Iwata et al also differs greatly from the present invention in other important respects.